diff --git a/src/Umbraco.Core/Models/EmailMessage.cs b/src/Umbraco.Core/Models/EmailMessage.cs
index e036f157d6..11483e1b20 100644
--- a/src/Umbraco.Core/Models/EmailMessage.cs
+++ b/src/Umbraco.Core/Models/EmailMessage.cs
@@ -8,19 +8,28 @@ namespace Umbraco.Core.Models
         public string To { get; }
         public string Subject { get; }
         public string Body { get; }
-        public bool IsBodyHtml { get; set; } = false;
+        public bool IsBodyHtml { get; }
 
-        public EmailMessage(string from, string to, string subject, string body)
+        public EmailMessage(string from, string to, string subject, string body, bool isBodyHtml)
         {
-            if (string.IsNullOrEmpty(from)) throw new ArgumentException("Value cannot be null or empty.", nameof(from));
-            if (string.IsNullOrEmpty(to)) throw new ArgumentException("Value cannot be null or empty.", nameof(to));
-            if (string.IsNullOrEmpty(subject)) throw new ArgumentException("Value cannot be null or empty.", nameof(subject));
-            if (string.IsNullOrEmpty(body)) throw new ArgumentException("Value cannot be null or empty.", nameof(body));
+            if (from == null) throw new ArgumentNullException(nameof(from));
+            if (from.Length == 0) throw new ArgumentException("Value cannot be empty.", nameof(from));
+
+            if (to == null) throw new ArgumentNullException(nameof(to));
+            if (to.Length == 0) throw new ArgumentException("Value cannot be empty.", nameof(to));
+
+            if (subject == null) throw new ArgumentNullException(nameof(subject));
+            if (subject.Length == 0) throw new ArgumentException("Value cannot be empty.", nameof(subject));
+
+            if (body == null) throw new ArgumentNullException(nameof(body));
+            if (body.Length == 0) throw new ArgumentException("Value cannot be empty.", nameof(body));
 
             From = from;
             To = to;
             Subject = subject;
             Body = body;
+
+            IsBodyHtml = isBodyHtml;
         }
     }
 }
diff --git a/src/Umbraco.Infrastructure/HealthCheck/NotificationMethods/EmailNotificationMethod.cs b/src/Umbraco.Infrastructure/HealthCheck/NotificationMethods/EmailNotificationMethod.cs
index 65fa7e3d47..37a3b5b072 100644
--- a/src/Umbraco.Infrastructure/HealthCheck/NotificationMethods/EmailNotificationMethod.cs
+++ b/src/Umbraco.Infrastructure/HealthCheck/NotificationMethods/EmailNotificationMethod.cs
@@ -82,10 +82,8 @@ namespace Umbraco.Web.HealthCheck.NotificationMethods
             if (string.IsNullOrWhiteSpace(subject))
                 subject = "Umbraco Health Check Status";
 
-            return new EmailMessage(to, RecipientEmail, subject, message)
-            {
-                IsBodyHtml = message.IsNullOrWhiteSpace() == false && message.Contains("<") && message.Contains("</")
-            };
+            var isBodyHtml = message.IsNullOrWhiteSpace() == false && message.Contains("<") && message.Contains("</");
+            return new EmailMessage(to, RecipientEmail, subject, message, isBodyHtml);
         }
     }
 }
diff --git a/src/Umbraco.Infrastructure/Services/Implement/NotificationService.cs b/src/Umbraco.Infrastructure/Services/Implement/NotificationService.cs
index e7adf79e08..83d1176402 100644
--- a/src/Umbraco.Infrastructure/Services/Implement/NotificationService.cs
+++ b/src/Umbraco.Infrastructure/Services/Implement/NotificationService.cs
@@ -435,7 +435,7 @@ namespace Umbraco.Core.Services.Implement
             }
 
             // create the mail message
-            var mail = new EmailMessage(fromMail, mailingUser.Email, subject, body) {IsBodyHtml = isBodyHtml};
+            var mail = new EmailMessage(fromMail, mailingUser.Email, subject, body, isBodyHtml);
 
             return new NotificationRequest(mail, actionName, mailingUser.Name, mailingUser.Email);
         }
diff --git a/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs b/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
index 89840a8696..511254e96b 100644
--- a/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
+++ b/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
@@ -322,10 +322,7 @@ namespace Umbraco.Web.BackOffice.Controllers
                         // Ensure the culture of the found user is used for the email!
                         UmbracoUserExtensions.GetUserCulture(identityUser.Culture, _textService, _globalSettings));
 
-                    var mailMessage = new EmailMessage(from, user.Email, subject, message)
-                    {
-                        IsBodyHtml = true
-                    };
+                    var mailMessage = new EmailMessage(from, user.Email, subject, message, true);
 
                     await _emailSender.SendAsync(mailMessage);
 
diff --git a/src/Umbraco.Web.BackOffice/Controllers/UsersController.cs b/src/Umbraco.Web.BackOffice/Controllers/UsersController.cs
index 0776e757e3..89322ede60 100644
--- a/src/Umbraco.Web.BackOffice/Controllers/UsersController.cs
+++ b/src/Umbraco.Web.BackOffice/Controllers/UsersController.cs
@@ -542,10 +542,7 @@ namespace Umbraco.Web.BackOffice.Controllers
                 UmbracoUserExtensions.GetUserCulture(to.Language, _localizedTextService, _globalSettings),
                 new[] { userDisplay.Name, from, message, inviteUri.ToString(), fromEmail });
 
-            var mailMessage = new EmailMessage(fromEmail, to.Email, emailSubject, emailBody)
-            {
-                IsBodyHtml = true
-            };
+            var mailMessage = new EmailMessage(fromEmail, to.Email, emailSubject, emailBody, true);
 
             await _emailSender.SendAsync(mailMessage);
         }